In oilfield operations, reciprocating pumps are used for different applications such as fracturing the subterranean formation, cementing the wellbore, or treating the wellbore and/or formation. A reciprocating pump typically includes a power end and a fluid end or cylindrical section. The fluid end is typically formed of a one piece construction or a series of blocks secured together by rods. The fluid end includes an opening for receiving a plunger or plunger throw, an inlet passage, an outlet passage, and an access port. Reciprocating pumps are oftentimes operated at pressures of 10,000 pounds per square inch (psi) and upward to 25,000 psi and at rates of up to 1,000 strokes per minute or even higher during fracturing operations. A reciprocating pump designed for fracturing operations is referred to as a frac pump.
During operation of a frac pump, a fluid is pumped into the fluid end through the inlet passage and out of the pump through the outlet passage. The inlet and outlet passages each include a valve assembly, which is a check type of valve that is opened by differential pressure of the fluid and allows the fluid to flow in only one direction. This fluid often contains solid particulates or corrosive material that can cause corrosion, erosion and/or pitting on surfaces of the valve assembly. One particular area of erosion and pitting generally occurs on interacting surfaces of the valve assembly, which consists of a valve seat fixed into the inlet or outlet passages within the fluid end and a valve body that moves cyclically relative to the valve seat. In operation, the valve is operable between an open position, in which the valve body is spaced apart from the valve seat to facilitate fluid flow through the valve, and a closed position, in which the valve body contacts and sealingly engages the valve seat.
During operation, solid particulates are oftentimes trapped between the interacting surfaces of the valve body and the valve seat, causing erosion and pitting of these surfaces. Because the valve seat is securely fastened within the fluid end, it is more difficult and cumbersome to replace the valve seat than the valve body. For example, a valve seat is oftentimes fixed inside the fluid passageway by way of an interference fit; thus, removing the valve seat from the fluid passageway oftentimes increases the risk of damage to the pump fluid end. There is a need to provide a valve having an increased resistance to wear to address one or more of the foregoing issues, among others.